区间桁架结构动力特性分析的区间因子法

对于具有区间参数的桁架结构的动力特性分析问题,提出了一种新的分析方法即区间因子法。利用区间因子法,结构材料物理参数、几何尺寸均可表达为其区间因子和确定性量的乘积,进而结构的固有频率和振型也可显式表达成区间因子们的函数。利用区间算法,推导出了结构固有频率和振型的上、下限与均值的计算表达式。通过算例,分析了结构参数的不确定性对结构动力特性的影响,并验证了本文模型和方法的合理性与可行性。本文方法的优点是能够反映结构某一参数的不确定性对结构动力特性的影响。

Interval Factor Method for Analyzing Interval Truss Structural Dynamic Characteristics

A new method called the interval factor method(IFM) for structural dynamic characteristics analysis of truss structures with interval parameters is presented,where the structural physical parameters and geometric dimensions can be expressed as the product of two parts corresponding to the interval factors and the deterministic value,and the structural natural frequency and mode shape can be expressed as the functions of the interval factors.The computational expressions for the lower,upper bonds and mean value of structural natural frequency and mode shape are developed by means of the interval operations.The effects of the uncertainty of the structural parameters on the uncertainty of the structural dynamic characteristic are analyzed via a simulation,and the model and method presented are verified.The method enables to reflect the effect from the uncertainty of each individual parameters on the structural natural frequency and mode shape.